Growth and Development

  • Development of secondary sex characteristics. During puberty, changing hormonal levels play a role in activating the development of secondary sex characteristics. These include: (1) growth of pubic hair; (2) menarche (first menstrual period for girls) or penis growth (for boys); (3) voice changes (for boys); (4) growth of underarm hair; (5) facial hair growth (for boys); and (6) increased production of oil, increased sweat gland activity, and the beginning of acne.
  • Continued brain development. Recent research suggests that teens’ brains are not completely developed until late in adolescence. Specifically, studies suggest that the connections between neurons affecting emotional, physical and mental abilities are incomplete. This could explain why some teens seem to be inconsistent in controlling their emotions, impulses, and judgments.

How Do These Changes Affect Teens?

  • Teens frequently sleep longer. Research suggests that teens actually need more sleep to allow their bodies to conduct the internal work required for such rapid growth. On average, teens need about 9 1/2 hours of sleep a night.
  • Teens may be more clumsy because of growth spurts. If it seems to you that teens’ bodies are all arms and legs then your perception is correct. During this phase of development, body parts don’t all grow at the same rate. This can lead to clumsiness as the teen tries to cope with limbs that seem to have grown overnight. Teens can appear gangly and uncoordinated.
  • Teenage girls may become overly sensitive about their weight. This concern arises because of the rapid weight gain associated with puberty. Sixty percent of adolescent girls report that they are trying to lose weight. A small percentage of adolescent girls (1-3%) become so obsessed with their weight that they develop severe eating disorders such as anorexia nervosa or bulimia. Anorexia nervosa refers to starvation; bulimia refers to binge eating and vomiting.  (more)